2. The Axilla Region
• The axilla is the name
given to an area that lies
underneath the
glenohumeral joint, at
the junction of the upper
limb and the thorax.
• It is a passageway by
which neurovascular and
muscular structures can
enter and leave the
upper limb.
3. Borders
• The overall 3D shape of the axilla looks slightly like a pyramid.
The borders consist of four sides and a base with an opening at
the apex.
– Apex – Also known as the axillary inlet, this is formed by lateral
border of the first rib, superior border of scapula, and the posterior
border of the clavicle.
– Lateral wall – Formed by intertubercular groove of the humerus.
– Medial wall – Consists of the serratus anterior and the thoracic wall
(ribs and intercostal muscles).
– Anterior wall – Contains the pectoralis major and the underlying
pectoralis minor and the subclavius muscles.
– Posterior wall – Formed by the subscapularis, teres major and
latissimus dorsi.
• The size and shape of the axilla region varies with arm
abduction. It decreases in size most markedly when the arm is
fully abducted – at this point, the contents of the axilla are at
most risk of injury.
5. Contents
• The main, and clinically important contents of the axilla region
include muscles, nerves, vasculature and lymphatics:
• Axillary artery – It is the main artery supplying the upper limb. It is
commonly referred as having three parts, one medial to the
pectoralis minor, one posterior to pectoralis minor, and one lateral to
pectoralis minor. The medial and posterior parts travel in the axilla.
• Axillary vein – The main vein draining the upper limb, its two largest
tributaries are the cephalic and basilic veins.
• Brachial plexus – A collection of spinal nerves that form the
peripheral nerves of the upper limb.
• Biceps brachii and coracobrachialis – These muscle tendons move
through the axilla, where they attach to the coracoid process of the
scapula.
• Axillary Lymph nodes – The axillary lymph nodes filter lymph that
has drained from the upper limb and pectoral region. In women,
axillary lymph node enlargement is a non-specific indicator of breast
cancer.
7. Passageways Exiting the Axilla
• There are three main routes by which structures leave the
axilla.
– The main route of exit is immediately inferiorly and laterally,
into the upper limb. The majority of contents of the axilla region
leave by this method.
– Another pathway is via the quadrangular space. This is a gap in
the posterior wall of the axilla, allowing access to the posterior
arm and shoulder area. Structures passing through include the
axillary nerve and posterior circumflex humeral artery (a branch
of the axillary artery.
– The last passageway is the clavipectoral triangle, which is an
opening in the anterior wall of the axilla. It is bounded by the
pectoralis major, deltoid, and clavicle. The cephalic vein enters
the axilla via this triangle, while the medial and lateral pectoral
nerves leave.
9. Clinical Relevance
Thoracic Outlet Syndrome
• The apex of the axilla region is an opening between the
clavicle, first rib and the scapula.
• In this apex, the vessels and nerves may become
compressed between the bones – this is called thoracic
outlet syndrome.
• Common causes of TOS are trauma (e.g fractured
clavicle) and repetitive actions (seen commonly in
occupations that require lifting of the arms)
• It often presents with pain in the affected limb, (where
the pain is depends on what nerves are affected),
tingling, muscle weakness and discolouration.
10. Lymph Node Biopsy
• Approximately 75% of lymph from the breast
drains into the axilla lymph nodes, so can be
biopsied if breast cancer is suspected.
• If breast cancer is confirmed, the axillary nodes
may need to be removed to prevent the cancer
spreading.
• This is known as axillary clearance.
• During this procedure, the long thoracic nerve
may become damaged, resulting in winged
scapula
12. The cubital fossa
• is an area of transition between the anatomical arm
and the forearm.
• It is located as a depression on the anterior surface of
the elbow joint.
• Borders
– The cubital fossa is triangular in shape, and thus has three
borders:
– Lateral border – The medial border of the brachioradialis
muscle.
– Medial border– The lateral border of the pronator teres
muscle.
– Superior border – An imaginary line between the
epicondyles of the humerus.
13. The cubital fossa..
• The floor of the cubital fossa is formed
proximally by the brachialis, and distally by the
supinator muscle.
• The roof consists of skin and fascia, and is
reinforced by the bicipital aponeurosis.
• Within the roof runs the median cubital vein,
which can be accessed for venepuncture
14. Contents of the cubital fossae
• The contents of the cubital fossa include vessels, nerves
and the biceps tendon (lateral to medial):
1. Radial nerve – This is not always strictly considered part of
the cubital fossa, but is in the vicinity, passing underneath the
brachioradialis muscle. As is does so, the radial nerve divides
into its deep and superficial branches.
2. Biceps tendon – It runs through the cubital fossa, attaching to
the radial tuberosity, just distal to the neck of the radius.
3. Brachial artery – The brachial artery supplies oxygenated
blood the forearm. It bifurcates into the radial and ulnar
arteries at the apex of the cubital fossa.
4. Median nerve – Leaves the cubital between the two heads of
the pronator teres. It supplies the majority of the flexor
muscles in the forearm.
• Mnemonic for contents of the cubital fossa – Really Need
Beer To Be At My Nicest.
15. Contents of the cubital fossa
Mnemonic for contents of the cubital fossa - Really Need Beer To Be At My Nicest.
16. Clinical Relevance
1. Brachial Pulse and Blood Pressure
– The brachial pulse can be felt by palpating immediately medial to the biceps
tendon in the cubital fossa. When measuring blood pressure, this is also the
location in which the stethoscope must be placed, to hear the korotkoff
sounds.
2. Venepuncture
– The median cubital vein is located superficially within the roof of the cubital
fossa. It connects the basilic and cephalic veins, and can be accessed easily
– this makes it a common site for venepuncture.
3. Supracondylar Fractures
– A supracondylar fracture usually occurs by falling on a flexed elbow. It is a
transverse fracture, spanning between the two epicondyles.
– The displaced fracture fragments may impinge and damage the contents of
the cubital fossa.
– Direct damage, or post-fracture swelling can cause interference to the blood
supply of the forearm from the brachial artery. The resulting ischaemia can
cause Volkmann’s ischaemic contracture – uncontrolled flexion of the
hand, as flexors muscles become fibrotic and short.
– There also can be damage to the median or radial nerves.
17. The Carpal Tunnel
• The carpal tunnel is a narrow passageway found
on the anterior portion of the wrist.
• It serves as the entrance to the palm for several
tendons and the median nerve.
Borders
• The carpal tunnel is formed by two layers: a deep
carpal arch and a superficial flexor retinaculum.
• The deep carpal arch forms a concave surface,
which is converted into a tunnel by the overlying
flexor retinaculum.
18. Carpal Arch
• Concave on the palmar side, forming the base
and sides of the carpal tunnel.
• Formed laterally by the scaphoid and
trapezium tubercles
• Formed medially by the hook of the hamate
and the pisiform
19. Flexor Retinaculum
• Thick connective tissue which forms the roof
of the carpal tunnel.
• Turns the carpal arch into the carpal tunnel by
bridging the space between the medial and
lateral parts of the arch.
• Originates on the lateral side and inserts on
the medial side of the carpal arch.
21. Contents
• The carpal tunnel contains a total of 9
tendons, surrounded by synovial sheaths, and
the median nerve.
• The palmar cutaneous branch of the median
nerve is given off prior to the carpal tunnel,
travelling superficially to the flexor
retinaculum.
22. Tendons
• The tendon of flexor pollicis longus
• Four tendons of flexor digitorum profundus
• Four tendons of flexor digitorum superficialis
• The 8 tendons of the flexor digitorum profundus and
flexor digitorum superficialis are surrounded by a single
synovial sheath. The tendon of flexor pollicis longus is
surrounded by its own synovial sheath. These sheaths
allow free movement of the tendons.
• Sometimes you may hear that the carpal tunnel contains
another tendon, the flexor carpi radialis tendon, but this
is located within the flexor retinaculum and not within
the carpal tunnel itself!
24. Median Nerve
• Once it passes through the carpal tunnel, the
median nerve divides into 2 branches: the
recurrent branch and palmar digital nerves.
• The palmar digital nerves give sensory
innervation to the palmar skin and dorsal nail
beds of the lateral three and a half digits.
• They also provide motor innervation to the
lateral two lumbricals.
• The recurrent branch supplies the thenar muscle
group.
25. Clinical Relevance: Carpal Tunnel
Syndrome
• Compression of the median nerve within the carpal tunnel can
cause carpal tunnel syndrome (CTS). It is the most common
mononeuropathy and can be caused by thickened ligaments and
tendon sheaths. Its aetiology is, however, most often idiopathic. If
left untreated, CTS can cause weakness and atrophy of the thenar
muscles.
• Clinical features include numbness, tingling and pain in the
distribution of the median nerve. The pain will usually radiate to
the forearm. Symptoms are often associated with waking the
patient from their sleep and being worse in the mornings.
• Tests for CTS can be performed during physical examination:
• Tapping the nerve in the carpal tunnel to elicit pain in median nerve
distribution (Tinel’s Sign)
• Holding the wrist in flexion for 60 seconds to elicit numbness/pain
in median nerve distribution (Phalen’s manoeuvre)
• Treatment involves the use of a splint, holding the wrist in
dorsiflexion overnight to relieve symptoms. If this is
unsuccessful, corticosteroid injections into the carpal tunnel can be
used. In severe case, surgical decompression of the carpal tunnel
may be required.
28. The Anatomical Snuffbox
• The anatomical snuffbox (also known as the
radial fossa), is a triangular depression found on
the lateral aspect of the dorsum of the hand.
• It is located at the level of the carpal bones, and
best seen when the thumb is abducted.
• In the past, this depression was used to hold
snuff (ground tobacco) before inhaling via the
nose – hence it was given the name ‘snuffbox’.
29. Borders of the Anatomical Snuffbox
• As the snuffbox is triangularly shaped, it has
three borders, a floor, and a roof:
• Ulnar (medial) border: Tendon of the extensor
pollicis longus.
• Radial (lateral) border: Tendons of the abductor
pollicis longus and extensor pollicis brevis.
• Proximal border: Styloid process of the radius.
• Floor: Carpal bones; scaphoid and trapezium.
• Roof: Skin.
31. Contents of anatomical Snuffbox
• The main contents of the anatomical snuffbox are the
radial artery, a branch of the radial nerve, and
the cephalic vein.
• The radial artery crosses the floor of the anatomical
snuffbox in an oblique manner. It runs deep to the
extensor tendons. The radial pulse can be palpated in
some individuals by placing two fingers on the proximal
portion of the anatomical snuffbox.
• Subcutaneously, terminal branches of the superficial
branch of the radial nerve run across the roof of the
anatomical snuffbox, providing innervation to the skin of
the lateral 3 1/2 digits on the dorsum of the hand, and
the associated palm area.
• Also subcutaneously, the cephalic vein crosses the
anatomical snuffbox, having just arisen from the dorsal
venous network of the hand.
33. Clinical Relevance: Fractures of the
Scaphoid
• In the anatomical snuffbox, the scaphoid and the
radius articulate to form part of the wrist joint. In the
event of a blow to the wrist (e.g falling on an
outstretched hand), the scaphoid takes most of the
force. If localised pain is reported in the anatomical
snuffbox, a fracture of the scaphoid is the most likely
cause.
• The scaphoid has a unique blood supply, which runs
distal to proximal. A fracture of the scaphoid can
disrupt the blood supply to the proximal portion – this
is an emergency. Failure to revascularise the scaphoid
can lead to avascular necrosis, and future arthritis for
the patient.
35. The Inguinal Canal
• The inguinal canal is a short passage that extends
inferiorly and medially, through the inferior part of
the abdominal wall. It is superior and parallel to
the inguinal ligament.
• It acts as a pathway by which structures can pass
from the abdominal wall to the external genitalia.
• The inguinal canal also has clinical importance. It is
a potential weakness in the abdominal wall, and
therefore a common site of herniation.
37. Development of the Inguinal Canal in
men
• During development, the testes establish in the posterior
abdominal wall, and descend into the scrotum.
• A fibrous cord of tissue called the gubernaculum attaches the
inferior portion of the gonad to the future scrotum, and
guides them during their descent.
• The inguinal canal is the pathway by which the testes are able
to leave the abdominal cavity and enter the scrotum.
• In the embryological stage, the canal is flanked by an out-
pocketing of the peritoneum, and the abdominal
musculature.
• This out-pocketing (processus vaginalis) normally
degenerates, but a failure to do so can result in an indirect
inguinal hernia.
39. Development of inguinal canal in
women
• In women, there is also a gubernaculum, this
attaches the ovaries to the uterus and future
labia majora.
• Because the ovaries are attached to the uterus
by the gubernaculum, they are prevented from
descending as far as the testes, instead moving
into the pelvic cavity.
• The gubernaculum then becomes the ovarian
ligament, and round ligament of uterus.
40. ‘Mid-Inguinal Point’ and ‘Midpoint of
the Inguinal Ligament’
• The mid-inguinal point is halfway between the
pubic symphysis and the anterior superior iliac
spine. The femoral artery crosses into the lower
limb at this anatomical landmark.
• The midpoint of the inguinal ligament is exactly
as the name suggests. The inguinal ligament runs
from the pubic tubercle to the anterior superior
iliac spine, so the midpoint is halfway between
these structures. The opening to the inguinal
canal is located just above this point.
42. Boundaries
• The inguinal canal is made up of:
– Anterior and posterior walls
– Superficial and deep rings (openings)
– Roof and floor (or superior and inferior walls)
• The anterior wall is formed by the aponeurosis of the
external oblique, and reinforced by the internal oblique
muscle laterally.
• The posterior wall is formed by the transversalis fascia.
• The roof is formed by the transversalis fascia, internal
oblique and transversus abdominis.
• The floor is formed by the inguinal ligament (a ‘rolled up’
portion of the external oblique aponeurosis) and thickened
medially by the lacunar ligament.
44. NB.
• During periods of increased intra-abdominal
pressure, the abdominal viscera are pushed
into the inguinal canal.
• To prevent herniation, the muscles of the
anterior and posterior wall contract, and
‘clamp down’ on the canal.
45. INGUINAL RINGS
• The two openings to the inguinal canal are known as rings.
1. The deep (internal) ring:
– is found above the midpoint of the inguinal ligament which is
lateral to the epigastric vessels.
– The ring is created by the transversalis fascia, which
invaginates to form a covering of the contents of the inguinal
canal.
2. The superficial (external) ring:
– marks the end of the inguinal canal, and lies just superior to
the pubic tubercle.
– It is a triangle shaped opening, formed by the evagination of
the external oblique, which forms another covering of the
inguinal canal contents.
– This opening contains intercrural fibres, which run
perpendicular to the aponeurosis of the external oblique and
prevent the ring from widening.
47. Contents
• In men, the spermatic cord passes through the
inguinal canal, to supply and drain the testes.
• In women, the round ligament of uterus
traverses through the canal.
• The walls of the inguinal canal are usually
collapsed around their contents, preventing
other structures from potentially entering the
canal and becoming stuck.
48. Clinical Relevance: Direct and Indirect
Inguinal Hernias
• A hernia is defined as the protrusion of an organ
or fascia through the wall of a cavity that
normally contains it.
• Hernias involving the inguinal canal can be
divided into two main categories:
– Indirect – where the peritoneal sac enters the inguinal
canal through the deep inguinal ring.
– Direct – where the peritoneal sac enters the inguinal
canal though the posterior wall of the inguinal canal.
• Both types of inguinal hernia can present as
lumps in the scrotum or labia majora.
49. Indirect Inguinal Hernias
• This classification of hernia is the more common. It
has a congenital origin – due to the failure of the
processus vaginalis to regress.
• The peritoneal sac enters the inguinal canal via the
deep inguinal ring. The degree to which the sac
herniates depends on the amount of processus
vaginalis still present.
• As the sac moves through the inguinal canal, it
acquires the same three coverings as the contents of
the canal.
50. Direct Inguinal Hernias
• In contrast to the indirect hernia, this is
acquired in origin, due to weakening in the
abdominal musculature.
• The peritoneal sac originates from an
area medial to the epigastric vessels and
bulges into the inguinal canal via the posterior
wall.
52. The Femoral Triangle
• The femoral triangle is
a hollow area in the
anterior thigh.
• Many large
neurovascular
structures pass through
this area, and can be
accessed relatively
easily.
53. Borders
• Superior border – Formed by the inguinal ligament,
a ligament that runs from the anterior superior iliac
spine to the pubis tubercle.
• Lateral border – Formed by the medial border of
the sartorius muscle.
• Medial border – Formed by the medial border of
the adductor longus muscle. The rest of this muscle
forms part of the floor of the triangle.
– Note: Some sources consider the lateral border of the
adductor longus to be the medial border of the femoral
triangle. However, the majority state that it is the medial
border of the adductor longus
54. borders
• It also has a floor and a roof:
– Anteriorly, the roof of the femoral triangle is formed
by the fascia lata.
– Posteriorly, the base of the femoral triangle is
formed by the pectineus, iliopsoas and adductor
longus muscles.
• The inguinal ligament acts as a flexor
retinaculum, supporting the contents of the
femoral triangle during flexion at the hip.
56. Contents
• The femoral triangle contains some of the major
neurovascular structures of the lower limb. Its contents
(lateral to medial) are:
– Femoral nerve – Innervates the anterior compartment of the
thigh, and provides sensory branches for the leg and foot.
– Femoral artery – Responsible for the majority of the arterial
supply to the lower limb.
– Femoral vein – The great saphenous vein drains into the
femoral vein within the triangle.
– Femoral canal – A structure which contains deep lymph nodes
and vessels.
• The femoral artery, vein and canal are contained within a
fascial compartment – known as the femoral sheath
57. .
A good way of remembering the contents is using the acronym NAVEL:
N: Nerve.
A: Artery.
V: Vein.
E: Empty space (this is important as it allows the veins and lymph vessels
to distend, so they can cope with different levels of flow).
L: Lymph canal
58. Clinical Relevance of the Femoral
Triangle
• Femoral Pulse
– Just inferior to where the femoral artery crosses the inguinal
ligament, it can be palpated to measure the femoral pulse. The
femoral artery crosses exactly midway between the pubis
symphysis and anterior superior iliac spine. The presence of a
femoral pulse means that blood is reaching the lower extremity.
• Access to the Femoral Artery
– The femoral artery is located superficially within the femoral
triangle, and is thus easy to access. This makes it suitable for a
range of clinical procedures.
– One such procedure is coronary angiography. Here, the femoral
artery is catheterised with a long, thin tube. This tube is navigated
up the external iliac artery, common iliac artery, aorta, and into
the coronary vessels. A radio-opaque dye is then injected into the
coronary vessels, and any wall thickening or blockages can be
visualised via x-ray.
59. Clinical Relevance of the Femoral
Triangle
• Femoral Hernia
– A hernia is defined as “a condition in which part of
an organ is displaced and protrudes through the
wall of the cavity containing it“.
– In the case of femoral hernia, part of the bowel
pushes into the femoral canal, underneath the
inguinal ligament.
– This manifests clinically as a lump or bulge in the
area of the femoral triangle. It usually requires
surgical intervention to treat.
60. The Femoral Canal
• The femoral canal is an
anatomical
compartment, located
in the anterior thigh. It
is the smallest and most
medial part of the
femoral sheath.
• It is approximately
1.3cm long.
61. Borders
• The femoral canal is located in the anterior thigh, within the
femoral triangle.
• It can be thought of as a rectangular shaped compartment.
• It has four borders and an opening:
– Medial border – Lacunar ligament.
– Lateral border – Femoral vein.
– Anterior border – Inguinal ligament.
– Posterior border – Pectineal ligament, superior ramus of the pubic
bone, and the pectineus muscle
• The opening to the femoral canal is located at its superior
border, known as the femoral ring.
• The femoral ring is closed by a connective tissue layer –
the femoral septum.
• This septum is pierced by the lymphatic vessels exiting the
canal.
62. Contents
• The femoral canal contains:
– Lymphatic vessels – draining the deep inguinal
lymph nodes.
– Deep lymph node – the lacunar node.
– Empty space.
– Loose connective tissue.
• The empty space allows distension of the
adjacent femoral vein, so it can cope with
increased venous return, or increased intra-
abdominal pressure
63. Clinical Relevance: Femoral Hernia
• The femoral canal is of particular clinical importance, as it a
common site of bowel herniation.
• A hernia is defined as ‘where an internal part of the body
pushes through a weakness in the muscle or surrounding
tissue wall‘. In a femoral hernia, part of the small intestine
protrudes through the femoral ring.
• It presents as a lump situated inferolaterally to the pubic
tubercle. This type of herniation is more common in women,
due to their wider bony pelvis.
• The borders of the femoral canal are tough, and not
particularly extendible. This can compress the hernia,
interfering with its blood supply. A hernia with a compromised
blood supply is known as a strangulated hernia.
64. The Adductor Canal
• The adductor canal (Hunter’s canal, subsartorial
canal) is a narrow conical tunnel located in the
thigh.
• It is 15cm long, extending from the apex of the
femoral triangle to the adductor hiatus of the
adductor magnus.
• The canal serves as a passageway from
structures moving between the anterior thigh
and posterior leg.
65. Borders
• The adductor canal is bordered by muscular
structures:
– Anterior: Sartorius.
– Lateral: Vastus medialis.
– Posterior: Adductor longus and adductor magnus.
– The apex of the adductor canal is marked by the
adductor hiatus – a gap between the adductor
and hamstring attachments of the adductor
magnus.
67. Contents
• The adductor canal serves as a passageway from
structures moving between the anterior thigh
and posterior leg.
• It contains the femoral artery, femoral vein, nerve
to the vastus medialis and the saphenous nerve
(the largest cutaneous branch of the femoral
nerve).
• As the femoral artery and vein exit the canal, they
become the popliteal artery and vein
respectively.
68. Clinical Relevance – Adductor Canal
Block
• In the adductor canal block, local anaesthetic is
administered in the adductor canal to block the
saphenous nerve in isolation, or together with
the nerve to the vastus medialis.
• The block can be used to provide sensory
anaesthesia for procedures involving the distal
thigh and femur, knee and lower leg on the
medial side.
• The sartorius and femoral artery are used as
anatomical landmarks to locate the saphenous
nerve.
69. Clinical Relevance – Adductor Canal
Compression Syndrome
• Adductor canal compression syndrome describes
entrapment of the neurovascular bundle within
the adductor canal.
• A rare condition, it is usually caused by
hypertrophy of adjacent muscles such as vastus
medialis.
• It is most common in young males, who may
present with claudication symptoms due to
femoral artery occlusion (more common) or
neurological symptoms due to entrapment of the
saphenous nerve.
70. The Popliteal Fossa
• The popliteal fossa is a
diamond shaped area
found on the posterior
side of the knee.
• It is the main path in
which structures move
from the thigh to the
leg.
71. Borders
• The popliteal fossa is diamond shaped, with four borders.
• These borders are formed by the muscles in the posterior
compartment of the leg and thigh:
– Superomedial border: Semimembranosus.
– Superolateral border: Biceps femoris.
– Inferomedial border: Medial head of the gastrocnemius.
– Inferolateral border: Lateral head of the gastrocnemius and
plantaris.
• The popliteal fossa also has a floor and a roof.
• The floor of the popliteal fossa is formed by the posterior
surface of the knee joint capsule, and by the posterior
surface of the femur.
• The roof is made of up two layers; popliteal fascia and
skin. The popliteal fascia is continuous with the fascia lata
of the leg.
72. Contents
• The popliteal fossa is
the main conduit for
neurovascular
structures entering and
leaving the leg.
• Its contents are (medial
to lateral):
– Popliteal artery
– Popliteal vein
– Tibial nerve
– Common fibular nerve
73. Contents…
• The tibial and common fibular nerves are the most
superficial of the contents of the popliteal fossa.
• They are both branches of the sciatic nerve.
• The common fibular nerve follows the biceps femoris
tendon, running along the lateral margin of the popliteal
fossa.
• The small saphenous vein pierces the popliteal fascia of
the popliteal fossa to enter the diamond, and empty into
the popliteal vein.
• In the popliteal fossa, the deepest structure is the popliteal
artery.
• It is a continuation of the femoral artery, and travels into
the leg to supply it with blood.
74. Clinical Relevance: Swelling in the
Popliteal Fossa
• he appearance of a mass in the popliteal fossa
has many differential diagnoses.
• The two major causes are baker’s cyst and
aneurysm of the popliteal artery.
75. Baker’s Cyst
• A baker’s cyst (or popliteal cyst) refers to the
inflammation and swelling of the
semimembranosus bursa – a fluid filled sac
found in the knee joint.
• The usually arise in conjunction with arthritis
of the knee (rheumatoid or osteoarthritis).
• Whilst it usually self-resolves, the cyst can
rupture and produce symptoms similar to
deep vein thrombosis.
77. Popliteal Aneurysm
• An aneurysm is a dilation of an artery, which is greater
than 50% of the normal diameter.
• The popliteal fascia (the roof of the popliteal fossa) is
tough and non-extensible, and so an aneurysm of the
popliteal artery has consequences for the other
contents of the popliteal fossa.
• The tibial nerve is particularly susceptible to
compression from the popliteal artery. The major
features of tibial nerve compression are:
– Weakened or absent plantar flexion
– Paraesthesia of the foot and posterolateral leg
